Many specific forms of chip control cutting inserts are known in the art including cemented carbide cutting inserts having parallel faces, generally diamond configuration, bottom recesses below the cutting edges and chip breaking walls projecting up from the bottom recess.
Special chip breaking effects have been achieved by providing a series of chip deflecting grooves or depressions spaced along the cutting edge such as disclosed in U.S. Pat. No. 4,215,957, 4,273,480 and 4,335,984. Recess grooves with chip breaking projections, particularly for use in turning operations are disclosed in U.S. Pat. No. 3,792,514, wherein a uniform concave groove is provided along each cutting edge in combination with a nose projection in the concave groove isolated from an island on the insert serving for chip breaking and light cutting operations.
Another form of such insert is disclosed in U.S. Pat. No. 4,214,845 including a pair of chip breaking projections at each corner with another projection on the bisector behind the first projections, as well as adjacent the center of each cutting edge. U.S. Pat. No. 3,815,192 discloses a polygonal throw away insert having a plurality of cutting edges on one major surface along the edges of all of the sides thereof and a plurality of projection rows provided on said surface along and spaced from the cutting edges so as to form chip breakers. Adjacent projections along each projection row define chip curling zones therebetween. The most relevant prior art known to applicants is illustrated in four perspective views of alternative commercial inserts identified in applicants' drawings as Prior Art FIGS. 8A-8D, the last of which is taken from U.S. Pat. No. 4,304,509.